Gradenigo Syndrome

Introduction:

This syndrome was first described by Gradenigo in 1907. He was an Italian Otologist. Maurice Lannois added vital data to those already described by Gradenigo. Gradenigo classically described the following as the classic features of this syndrome:

1. Discharging ear

2. Retro orbital pain

3. Adbucent nerve paralysis causing diplopia

Causative factors:

1. Uncontrolled mastoiditis

2. Epidural abscess following mastoiditis

Pathophysiology:

This syndrome has been known to occur due to spread of ear infection to involve air cells around petrous apex. It is hence also known as “Petrous apex syndrome” / “Petrous apicitis”. Infection & inflammation of petrous apex involves 6^th cranial nerve at the Dorello's canal and 5^th cranial nerve in the Meckel's cave. Meckel's cave lies close to Dorello's canal. Retro orbital pain is caused due to the involvement of trigeminal ganglion (Gessarian ganglion) at the level of Meckel's cave.

Clinical features:

1. Intense head ache (most commonly retro orbital pain)

2. Discharging ear

3. 6^th nerve palsy & diplopia

4. Horner's syndrome rarely if sympathetic plexus around internal carotid artery is involved at the level of petrous apex

Pain could be caused by any of the following mechanisms:

1. Referred otalgia

2. Dural irritation in the tegmen area

3. Inflammation of Gessarian ganglion

4. Localized meningitis

It is clearly not known how long it takes for infection to spread from mastoid air cells to petrous apex. Studies have shown that this interval can vary between 1 week to 3 months. The spread of infection from mastoid air cell system to petrous apex depends on the following factors:

1. Type and virulence of the infecting organism

2. Host immunity

3. Pneumatization of petrous apex area – If this area is not pneumatized then infection from mastoid air cell system cannot spread to this critical area.

4. Children are commonly involved because the common infecting organims in them is H. Influenza which is known to spread rapidly.

Role of Imaging:

High resolution CT scan and MRI studies help in clinching the diagnosis. CT scan reveals clouding of mastoid and petrous air cells. MRI is useful in patients with suspected lateral sinus thrombophlebitis which may be an associated condition in these patients.

Complications:

The proximity of various venous sinuses to the petrous apex has been attributed to be the cause for various complications following Gradenigo syndrome. These complications include:

1. Thrombosis involving various venous sinuses

2. Meningitis

3. Epidural abscess

4. Brain abscess

5. Palsies involving various cranial nerves

6. Horner's syndrome

7. Prevertebral and parapharyngeal abscesses

Management:

Intravenous broad spectrum antibiotics should be started immediatly. If there is associated lateral thrombophlebitis then anticoagulants should be considered. After a week of antibiotic therapy if the patient does not show any signs of recovery then mastoidectomy should be resorted to. In children with gradenigo syndrome with assocaited lateral sinus thrombophlebitis surgery should be resorted to at the earliest.

Intravenous antibiotic regimen:

1. Vancomycin 60 mg /kg/day – 10 days

2. Cefotaxime 275 mg /kg / day – 7 days

Role of steroids:

Injection dexamethazone has been administered in these patients during acute phase in parenteral dose of 0.8 mg/kg/day. This dose ofcourse should be tapered.

Acute pain can be best managed by use of anti inflammatory drugs.

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